South Africa Climate & Hardiness Zones

My research is in Agriculture and as a result I am always on the lookout for climate & agricultural maps of South Africa. The government doesn’t do a good job at updating this information and the weather bureau wants you to pay them a lot of money for such info – on a shoe-string budget, buying information is unpractical – the university I used to study at does have their own archive, but it is a bit out dated (maps from 2000).

So, I have scouted the internet and in 2012 I found a very nice climate map that was made available by the CSIR and D. C. U. Conradie, I have posted it on my About page; but here it is again.

South Africa’s Climate Zones: Today, Tomorrow
International GreenBuilding Conference and Exhibition
Future Trends and Issues Impacting on the Built Environment 
D. C. U. Conradie2012 (CSIR data 2010)

Some of my vegetable books from Australia have the hardiness zones of South Africa, since the two countries have very similar climatic patterns. To prevent plagiarism I remade my own based on several sources. Most of the zones coincide with South Africa’s annual rainfall patterns. Recently I tried to get a hold of South Africa’s Hardiness Zones, and yet again without fail, I seem to turn up with nothing, nada, niks!

South Africa Hardiness Zones
Reconstructed visually from maps supplied by
Grow Your Own Fruit & Vegetables the easy way (AUS book) and Food From Your Garden (SA book)
Constructed with ArcGISOnline tools

Just a note on the map above; it is based on the Australian Hardiness Zones and not the USDA. Therefore it requires some clarification:

Zone 1: Hot arid	This region has a low rainfall (350 mm per annum) and is very dry. Rain falls during the summer in the north and during the winter in the south. Extended periods of drought are a regular occurrence. Daytime temperatures are 38oC-45oC, with little humidity. Night time temperatures drop drastically and frost is a regular occurrence in winter. Frosts can be severe in the southern regions and occur during late autumn to early spring.
Zone 2: Mediterranean	Zone 2 correlates with a winter rainfall pattern (350-1000 mm per annum), usually between late autumn and early spring. Summers are hot and dry with periodic droughts with an average daytime temperature below 30oC. As with most of SA, frost occurs more towards the inland than on the coast. This region has similar climate to the northern Mediterranean and southern California.
Zone 5: Cool subtropical	This zone contains a large chunk of the fynbos biome and the montane forest of SA. It is a coastal region with warm, moist conditions with an average temperature of 18oC to 24oC. Rainfall occurs throughout the year, 750-1250 mm per annum, with the heaviest during mid-summer and mid-autumn. Frost doesn’t occur along the coast, but towards the inland and around the mountains during mid-April to early October.
Zone 6: Warm Subtropical	This is an ideal zone for gardens with a hot, humid climate and summer rainfall pattern. Average temperatures are 20oC to 23oC and 750-1250 mm of annual rainfall. July to September is warm and sunny with little rain. Night temperatures don’t fall below 15oC – a good thing for growing peppers!!! Some inland areas experience frost, but the zone is mainly frost free.
Zone 7: Warm Semi-Arid	Average summer temperatures are mid-30oC or higher. Rain is monsoonal and occurs mainly during summer, 250-850 mm per annum, with more rain towards the coast. Extended periods of severe drought can occur far from the coast.  In the northern parts frost is restricted to July, but can occur throughout the winter in the south and can be heavy around mountains.

This is a general guideline to SA and given the amount of season shifting we have experience the last few years it may differ slightly at local regions and microclimatic conditions. To convert your AUS hardiness zone to USDA, simply add 7 to your AUS zone (for example, Roodepoort is Zone 7 AUS = 7 +7 = Zone 14 USDA).

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I hope this helps any other people looking for this info on SA! For any of those who want to create your own maps, check out www.arcgis.com; where you can create a free ArcGISOnline account to make basic maps or use QGIS open-source freeware!

Related Articles

• Seasonal Rainfall Update 2020
• Spring Garden Planner
• Autumn Garden Planner
• Winter Garden Planner
• Summer Garden Planner
• Sustainable South African Food Garden Part 1

Updates

– Update Dec 2017 –

I have found an interactive map for the South African Hardiness Zones @ www.plantmaps.com! It is based on the USDA hardiness zones scale, however it does not contain planting information…

– Update Jul 2020 –

Seeds for Africa has a very simple vegetable planting guide for all the provinces of South Africa